Help Measuring Shotgun gauge

[john12865]

I just picked up an older percussion sidelock shotgun for $50.00.

I'm not sure if this subject belongs in smoothbore or percussion.

Admin, Please administer 50 lashings. :blah:

My muzzleloading experience is with rifles. The breech looks to be 12 ga. the muzzle is 16 ga. Is this a 12 ga. full choke or a 16 ga. gun?
How does one measure gauge in a muzzleloading shotgun? At the breech or the muzzle?
I dumped 50 grs. down her throat when I got home and stuffed her with a patch just to see if she would fire. Went off with no problem.
If anyone has any advice on loads, shot and maximum safe powder charges please chime in. Thanks

 

[TN.Frank]

Gauge is the number you get when you take a lead ball of that bore size and figure out how many of those balls you'll get per lb of lead. A 12 bore, or gauge gun will give you 12 ball/lb of lead. But of course a person will normally use a ball smaller then the actual bore size and patch it up to fit.

 

[Rebel]

Mic the bore and see what size it is.

 

[john12865]

20 GA. at the bore. Anyone have suggestions for loads that would be effective for tree rats and or such varmits and the range one might expect? Barrel lenght is 28".

 

[Rebel]

If it is a true .20 ga then .20 ga wads should work. I use a thick overpowder wad, half a lubed fiber cushion wad, and then 65-70 grs of Goex 3f, 1 oz of #5 or #6 shot and an overshot card wad.

 

[john12865]

It's a start. Thanks! :grin:

 

[TANSTAAFL]

Measure at the muzzle or internal long reach calipers. TOW sells a brass gage/caliber measurement tool for just a couple of bucks.

 

[Capt. Jas.]

Shotguns are measured down in the bore away from the muzzle using a bore micrometer. The muzzle can then be measured and the difference will be the degree of choke in the gun. I dont ever assume it's cyl. bore.

 

[TANSTAAFL]

Shotguns are measured down in the bore away from the muzzle using a bore micrometer. The muzzle can then be measured and the difference will be the degree of choke in the gun. I dont ever assume it's cyl. bore.

When it comes to originals, prior to the late 1860's, chokes of any type for smooth bores was unknown. (blunderbuss was for ease of loading only)
[url] http://www.chrisbatha.com/clays1.html[/url]

The contested invention of shotgun choke between W. R. Pape, an Englishman, in 1866, and American Fred Kimble in 1870 was followed by W.W. Greener's research and development.

 

[Capt. Jas.]

[quote=TANSTAAFL When it comes to originals, prior to the late 1860's, chokes of any type for smooth bores was unknown. (blunderbuss was for ease of loading only)

That I am aware of. The gun was mentioned as an "older" sidelock. I posted about choke due to the fact many repro guns are being made choked or older ones have been choked and someone might want to know how to correctly measure. You still dont want to measure at the muzzle though.

 

[burch]

John,
Try this link:
[url] www.gunnersden.com/blackpowder/index.htm.blackpowder-shotguns.html[/url]

 

[TANSTAAFL]

Shotguns are measured down in the bore away from the muzzle using a bore micrometer. The muzzle can then be measured and the difference will be the degree of choke in the gun. I dont ever assume it's cyl. bore.

I merely clarified, that pre late 1960's (older) original "shotguns" were not choked.